2- -propionic acid herbicide

Kobek K., Focke M. and LTchtenthaler H.K., 1988. Fatty acid biosynthesis and acetyl-GoA carboxylase as a target of diclofop, fenoxaprop and other aryloxy-phenoxy-propionic acid herbicides. Z. Naturforsch. 43c, 47-54 Kreuzaler F. and Hahlbrock K., 1975. Enzymic Synthesis of an aromatic ring from acetate units. Eur J. Biochem. 205-213. 

Some propionic acid is converted iato herbicides (qv) such as Stam (Rohm and Haas) (3, 4 -dich1oropropionanilide) and iato ceUulose acetate propionate, a plastic sheeting and mol ding precursor. 

Figure 13.11 Column-switcliing RPLC trace of a surface water sample spiked with eight chlorophenoxyacid herbicides at the 0.5 p-g 1 level 1, 2,4-dichlorophenoxyacetic acid 2, 4-chloro-2-methylphenoxyacetic acid 3, 2-(2,4-diclilorophenoxy) propanoic acid 4, 2-(4-cliloro-2-methylphenoxy) propanoic acid 5, 2,4,5-trichlorophenoxyacetic acid 6, 4-(2,4-dichlorophenoxy) butanoic acid 7, 4-(4-chloro-2-methylphenoxy) butanoic acid 8, 2-(2,4,5-tiichlorophenoxy) propionic acid. Reprinted from Analytica Chimica Acta, 283, J. V. Sancho-Llopis et al., Rapid method for the determination of eight chlorophenoxy acid residues in environmental water samples using off-line solid-phase extraction and on-line selective precolumn switcliing , pp. 287-296, copyright 1993, with permission from Elsevier Science.

Only the R(+) enantiomer of the herbicide 2-(2-methyl-4-chlorophenoxy)propionic acid was degraded (Tett et al. 1994), although cell extracts of Sphingomonas herbicidovorans grown with the R(-) or S -) enantiomer, respectively, transformed selectively the R -) or S(-) substrates to 2-methyl-4-chlorophenol (Nickel et al. 1997). 

Natural systems may be quite complex. For example, the enantiomerization of phenoxyalkanoic acids containing a chiral side chain has been studied in soil using H20 (Buser and Muller 1997). It was shown that there was an equilibrium between the R- and 5-enantiomers of both 2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) and 2-(2,4-dichlorophenopxy)propionic acid (DCPP) with an equilibrium constant favoring the herbicidally active / -enantiomers. The exchange reactions... 

Zipper C, M Bunk, AJB Zehnder, H-PE Kohler (1998) Enantioselective uptake and degradation of the chiral herbicide dichloroprop [(R5)-2-(2,4-dichlorophenoxy)propionic acid] by Sphingomonas herbicidov-orans MH. J Bacteriol 180 3368-3374. 

Zipper C, K Nickel, W Angst, H-PE Kohler (1996) Complete microbial degradation of both enantiomers of the chiral herbicide Mecoprop [(R,S)-2-(4-chloro-2-methylphenoxy)]propionic acid in an enantioselective manner by Sphingomonas herbicidovorans sp. nov. Appl Environ Microbiol 62 4318-4322. 

The phenols (no. 30a, 30b, 32) are used as reactants to synthesize several of the company s products, including the benzotriazoles. The 2-chloro-4,6-bls-isopropylam-ino-s-triazine (no. 13) are herbicides the chloro compound is used to control weeds and grass in corn and in milo, and the methoxy compound is used for general plant control. Several esters of 3-(3 ,5 -di-t-butyl-4 -hydroxyphenyl) propionic acid were identified, the most abundant being the octadecyl and methyl esters. 

The polystyrene latexes produced from concentrated emulsions have been used as carriers for the controlled release of herbicides [160], The release of 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP) was found to depend on the water concentration, increasing with increasing dilution of the latex. High conversion to polymer was required to prevent a large initial release of herbicide on dilution however, a significant initial burst was still observed at almost complete conversion. This was reportedly due to dissolution of 2,4-DP at, or near, the surface of the latex particles. 

Dichlorophenoxy)acetic acid, together with the 2-methyl-4-chloro and the 2,4,5-trichloro analogs, 2-(2,4,5-trichlorophenoxy)propionic acid, and many other related compounds, constitute one of the major classes of herbicides, selective primarily to dicotyledonous plants. Monocotyledons,... 

Many other compounds have been included in studies on sucrose response. Most of these have been herbicides or enzyme poisons. None of the common herbicides had any positive effect on sucrose at rates up to that causing severe foliar injury. Earlier reports of response from 2-(2,4,5-trichlorophenoxy)propionic acid and 2,2-dichloropropionic acid could not be substantiated in British Guiana and Queensland. 27 Some compounds, such as 3-(p-chlorophenyl)-l,l-dimethylurea (monuron), (2,4-dichloro-phenoxy) acetic acid in soil, ethylenediaminetetraacetic acid, and leaf desiccants decreased sucrose and juice solids content. 20 Field trials with several chemicals in Trinidad showed enhanced sucrose at 14 to 28 days before harvest resulting from the application of 8 and 12 lb. (per acre) of... 

The other hydrocarbon acids arc not a industrially significant. In many potential markets the lower price of acetic acid keeps them blocked out. Formic acid is used in textile drying and leather treatment. Propionic acid is used in the production of propionates, plasticizers, and herbicides Butyric acid finds a variety of specialty uses in producing plasticizers and esters. 

BASF (Ludwigshafen, Germany) produces isomerically pure (i )-2-(4-hydroxy-phenoxy)-propionic acid (HPOPS) from (P)-2-phenoxypropionic add (POPS) on a 100 m3 fermenter scale for use as a herbicide intermediate (Figure 7.30) (Cooper, 1990). 

T, in turn, was used in the production of a wide variety of herbicides including Silvex (2-[2,4,5-trichlorophenoxy]propionic acid) and Agent Orange (Hutzinger et al. 1985). Hexachlorophene, which is currently under EPA suspension, is reported to contain <15 g/kg (ppb) 2,3,7,8-TCDD (IARC 1977 Sine 1990). 2,3,7,8-TCDD is an unwanted by-product formed during the production of hexachlorophene (Freeman et al. 1986). The 2,3,7,8-TCDD produced is primarily contained in still-... 

These workers [20] also examined thin layer chromatography of 2,4-DP (Dichloroprop) and MCPP (mixture of Mecoprop and 2-(2-chloro 4-methylphenoxy)propionic acid). In this method the ethyl ether extract of the sample is purified on a column of silicic acid and the herbicides are separated by thin layer chromatography on silica gel-kieselguhr (2 3) with light petroleum-acetic acid-kerosene (10 1 2) as solvent. The sensitivity is 3pg of either compound per litre, the average recoveries of Dichlorprop and MCPP are 85.7% and 87.4%, respectively, and the corresponding standard deviations were 13.9% and 15.5%. 

Chemical Name ( )-2-(2,4-dichlorophenoxy) propanoic acid ( )-2-(2,4-dichlorophenoxy) propionic acid Uses herbicide and growth regulator to control annual broadleaf and grass weeds also to control aquatic weeds and chemical maintenance of embankments and roadside verges. 

Soil t,/2 = 10 d in sandy soils and t,/2 30 d in sandy clay soils while under anaerobic conditions, results were similar except that the very rapid cleavage of the ester bond by hydrolysis within one hour to propionic acid derivatives was experienced and within 2 d, up to 86% of the parent compound was metabolized into various free acid metabolites and up to 3.7% of phenol metabolites (Herbicide Handbook 1989) ... 

Synonym Compitox, Duplosan, Hedonal, Iso-Cornox, Kilprop, MCPP, Mecopex, Mepro, Methoxone, Propal Chemical Name ( )-2-(4-chloro-2-methylphenoxy)propanoic acid ( )-2-(4-chloro-otolyl-oxy)propionic acid Uses herbicide for post-emergence control of broadleaf weeds in wheat, barley, rye, herbage seed crops, grassland, and under fruit trees and vines, etc. 

Propanil is one of a group of amide herbicides (made from aniline treated with organic acids), and is used extensively to control weeds in rice crops. Rice itself contains an enzyme that hydrolyzes propanil to 3,4-dichloroani-line and propionic acid, and so it is resistant to the herbicide. Weeds, lacking this enzyme, are adversely affected by it. (Mammalian liver cells also have an enzyme that causes this hydrolysis.)... 

Phenoxypropionic acid herbicides contain a stereogenic center that can be derived from 2-chloro-propionic acid and include fluazifop-butyl (29) and flamprop (30).245... 

TP [2-(2,4,5-trichlorophenoxy propionic acid], or silvex, is an herbicide that has been used for weed and brush control on rangeland and rights of way. It is soluble in water and its environmental resistance is expected to be relatively short. 2,4,5-TP is contaminated to varying extents with 2,3,7,8-TCDD, a toxic polychlorinated dibenzo-/j-dioxin. It has been classified in the EPA s Group D (not classifiable). 

Substituted phenols Chlorophenoxy compounds Substituted acetic and propionic acids Amides and thioamides Substituted ureas Carbamates and dithiocarbamates Symmetrical triazines Benzoic acid derivatives Miscellaneous herbicides... 

Preferred Name Dalapon sodium salt Synonyms Basfapon Basfapon B Basfapon/ Basfapon N BH Dalapon Basinex Crisapon Dalapon 85 Ded-Weed Devipon 2,2-Dicloro-propionic acid a-Dichloropropionic acid a,a-Dichloropropionic acid Dowpon Dowpon M Gramevin Kenapon Kyselina Liropon Proprop Radapon Revenge Unipon Chemical/Pharmaceutical/Other Class Chlorinated aliphatic herbicide Chemical Structure ... 

Pesticide uses Exemplars Herbicides 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), dicamba, mecoprop, 2-(2-methyl-4-chloro-phenoxy) propionic acid (MCPP)... 

Low levels of an applied herbicide-pesticide-solvent mix were drawn into the uptake air of a commercial building following the application of a pesticide mix to the lawn in front of that building. Several employees immediately reported CNS and respiratory symptoms, with one sustaining a permanent respiratory injury. The pesticide mix applied to the lawn was composed of 2,4-D (2.82), 2-(2-methyl-4-chlorophenoxy) propionic acid (MCPP 2.48), and dicamba (2.21). The mixture also contained solvent naphtha (a mixture of aliphatic solvents, Kqw = 3.5-5.0) with 14% naphthalene (2.48) and dinitroaniline (3.30). The concentrations of all pesticides and solvents were far below the TLVs both outside and inside the building. The toxic effects observed were ascribed to the mixture of lipophilic and hydrophilic pesticides. 441... 

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